Tsuji, like many people who survive cancer, decided she needed to change her diet. After all, it’s one way to wrest control over a body that has been so out-of-control. “To be honest, I don’t know if diet was a part of me getting cancer, but I wanted to do everything I could to make sure I was on the right path,” says the parent of two young boys.

Tsuji bought books on cancer-fighting diets, read up on the Internet about the latest nutritional findings and eventually enrolled in a four-week “How Foods Fight Cancer” cooking class offered at Pasadena’s Cancer Support Community (formally The Wellness Community). The class was the most eye-opening experience of all, she says, because there she realized that foods — especially plant foods — were the key to not only surviving but also preventing cancer. “What is taught in that class would work for anyone, not just cancer survivors,” she says. “People with high blood pressure, high cholesterol, people who want to prevent diabetes. All of us. It’s smart eating that makes sense.”

Indeed, much of the research on nutrition and cancer centers on plant foods with phytochemicals, great antioxidants that may foil cancerous growth. The media loves to tout such exotic foods as black rice, purple sweet potatoes and red açai berries as superfoods that will save us all. But eater, beware.

“There are no such things as cancer-fighting foods,” says Shiuan Chen, director of Tumor Cell Biology at City of Hope in Duarte. “There are foods you can eat that can have some effect in preventing or helping patients survive cancer. Foods cannot be used as a drug to treat cancer. Any food that claims to treat cancer…don’t believe it.”

Chen is currently researching three plant-based foods that have been shown to be effective in keeping cancer growth at bay: grapes, button mushrooms and red wine. He’s looking closely at these foods because they suppress aromatase (an enzyme involved in the production of estrogen), which can encourage the spread of certain cancers, especially those of the breast and prostate. Mushrooms have long been associated with health; studies in Korea and China show that people who eat more of the fungus have a lower incidence of breast cancer, Chen says. In his lab, Chen purified and concocted superconcentrated versions of mushrooms (1,000 times more potent than a typical one), which were studied to determine whether they could impact prostate cancer in men; results are now being analyzed.

Grapes and red wine are also under the microscope because of their ability to suppress aromatase; in grapes, it’s mainly the seeds that contain the highest concentration of phytochemicals. Again, Chen will be overseeing how superconcentrations of these chemicals act on cancerous cells, which may lead to further clinical trials. Chen is also interested in seeing what other researchers are discovering about blueberries, raspberries and pomegranates, but he’s quick to note that his studies — or any others — shouldn’t be taken as advice to eat just one food or, in the case of red wine, to start drinking.

“In general, most people need to diversify and eat more fruits and vegetables,” he says. “Mix it up and know that each one has something powerful in it that can help keep you healthy.”

Getting people to jump on the fruits-and-veggies bandwagon is the job of Leah Kurihara, oncology dietician at Huntington Hospital Cancer Center, who for 30 years has shepherded people through cancer diagnosis, treatment and aftercare. She also counsels people who are fighting the regret of less-than-healthy eating. “People want to blame their diet for their cancer, but honestly, there’s no way to prove that,” she says. “[People say] ‘I ate this and I got cancer.’ That may not be the case, but diet has an influence on you, so let’s get you on better terms with food right now.”

Rather than suggest specific cancer-fighting foods, Kurihara stresses a wide range of foods. She notes that one day a food can be heralded as helpful but later deemed otherwise. “Look at what we have learned about soy and breast cancer — not the best thing to be advocating for older women.” (Recent studies have shown that excessive soy may contribute to breast cancer in older women; the jury is still out on its effects when consumed by children.)

“Basically a cancer-prevention diet is a healthy diet that can apply to all of us,” Kurihara continues. “Avoid processed foods, sugary energy drinks and dense foods. Cut back on red meat and don’t rely on supplements. There is no evidence that they can prevent cancer.”

Some nutritionists go further, advocating veganism. Among them is Kate Oakland, who has been teaching “Foods that Fight Cancer” classes around Southern California for six years. Her course follows guidelines laid down by the Cancer Project, a program of Physicians for Responsible Medicine based in Washington, D.C., who advocate that people eat from four main food groups: fruits, vegetables, whole grains and legumes and beans. No dairy or meat because of their fat content; not even seafood, because of possible exposure to the neurotoxins known as PCBs.

“The main thing is to get the harmful foods out of your diet and that mostly means animal protein. We want people to eat plants and starches. And think about spices,” says Oakland. “In America, we think spice is just salt and pepper. There are cinnamon, cloves and turmeric, all with nutritional value and studies showing their protective nature.”

Oakland’s biggest challenge is to clear up the misconceptions about so-called cancer superfoods. “There is so much misinformation out there and it’s so easy for people to get confused,” she says. “Atkins told us that carbs were bad for us, but that’s simply not the case. If collard greens and broccoli had councils with marketing dollars…I’d be out of business.”

In her class, Oakland offers cooking demonstrations, recipe swaps and even an alternative milk sampling which really changes people’s perception of what milk is supposed to taste like. “What I love is when people say, ‘I hate fill-in-the-blank’ and then I make something with that in it, and they discover that, hey, this is pretty good,” she says citing her easy bean salad and fruit ambrosia. She also claims that she can create a smoothie with kale — yes, kale — that’s delicious.

For Oakland’s students, including Tsuji, changing to a new way of eating can be slow going, but the results are encouraging. “I dropped a lot of weight and I feel so much better,” she says. Still, there are temptations out there, especially when her family goes out to eat and orders tri-tip and macaroni and cheese. “I had the most wonderful portobello mushroom burger and years ago I wouldn’t have dreamed of ordering that,” she says. “Sure, there are days I get frustrated and I do miss certain foods, but I’m taking care of myself and my family. I’m learning to make every bite count.” ­

The next “How Food Fights Cancer” class is scheduled for Feb. 9 at the Pasadena Cancer Support Community Center, 200 E. Del Mar Blvd. The class runs from 1:30 to 3:30 p.m. For information and reservations, call Jill Searle at (626) 796-1083.